Proposition: Prop. 10.019: Product of Rational Numbers is Rational
Euclid's Formulation
The rectangle contained by rational straight lines (which are) commensurable in length is rational.
* For let the rectangle $AC$ have been enclosed by the rational straight lines $AB$ and $BC$ (which are) commensurable in length.
* I say that $AC$ is rational.
Modern Formulation
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Table of Contents
Proofs: 1
Mentioned in:
Proofs: 1 2 3 4 5 6 7 8 9
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References
Adapted from (subject to copyright, with kind permission)
 Fitzpatrick, Richard: Euclid's "Elements of Geometry"
Adapted from CC BYSA 3.0 Sources:
 Prime.mover and others: "Pr∞fWiki", https://proofwiki.org/wiki/Main_Page, 2016